This invention relates to velocipedes and more particularly to bicycles or tricycles in which the position of the pedals can be adjusted relative to a fixed seat location.
The most common method of adjusting the distance between a bicycle seat and the pedals is to mount the seat for vertical adjustment while the bicycle drive sprocket is mounted for rotation about a fixed axis relative to the bicycle frame. Another method, such as that shown in U.S. Pat. No. 2,602,777, permits the drive sprocket to be adjusted about the axis of the rear wheel. The latter has the disadvantage of also moving the entire drive chain vertically when the sprocket is being adjusted. There is therefore a need to provide a bicycle or tricycle in which the position of the pedals can be changed relative to the seat without changing the tension in the drive chain.